共查询到18条相似文献,搜索用时 171 毫秒
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设计了一种基于CCD的非接触尺寸测量系统.运用亚像素边缘检测法对圆环进行边缘检测,完成对圆环的非接触尺寸测量.利用数据库实现对测量数据的存储管理及网络传输.通过实验证明:对圆环测量精度外径误差0.005 mm,内径误差0.001 mm,壁厚误差0.015 mm,整体绝对误差小于0.02 mm,相对误差小于0.07%,满足了工程高精度测量要求.本系统适合有危害性的工业现场环境,数据的存储管理功能也给实际应用带来很大便利. 相似文献
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目前技术条件下,对于大视场的高精度边缘测量而言,工业级面阵CCD传感器的分辨率难以满足要求.文章针对钢板尺寸测量系统,首先介绍了测量环境和工作原理.继而在Zernike矩以及Zernike矩亚像素精度边缘检测原理的基础上,提出了适用于钢板尺寸测量的亚像素精度边缘检测算法.该算法不仅具较好的抗噪性能和检测精度,而且在传统界定边缘点的阈值处理方法上进行了改进,使边缘受限于单个像素的宽度范围内,能够实现亚像素精度的定位.系统实际运行表明,该方法能够有效提高测量精度,具有良好的效果和实用价值. 相似文献
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在电连接器插针缺陷检测系统中,插针图像特征点的获取是检测关键,为了实现插针位置的高精度检测,提出了一种基于Zernike矩的插针特征点定位算法。通过增大Zernike矩的算子模板尺寸,以及优化边缘阶跃模型,提高了亚像素边缘检测算法的精度。将最大熵阈值法应用于Zernike矩边缘检测算法,实现了自动选择最佳阈值,解决了传统算法中手动调节阈值的低效率问题。对提取的亚像素边缘点进行拟合获得椭圆目标中心,实现了插针的位置特征点提取。仿真实验与实际测试结果表明,该算法能够实现图像边缘的亚像素检测和插针特征点的准确定位,算法定位误差小于0.1个像素。 相似文献
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为了提高工件测量自动化程度和测量精度,设计了基于万能工具显微镜的非接触自动测量系统.对该系统所采用的图像去噪、边缘检测、亚像素定位等算法进行了研究;首先,在纵向和横向导轨上分别安装高精度光栅尺,用光栅信号采集卡采集纵向和横向光栅信号,经计算机数据处理获取被测物体测量尺寸整数部分;在工件检测目镜和纵向和横向读数目镜的位置上分别安装工件检测CCD和纵向和横向读数CCD,经过图像处理测得尺寸小数部分;然后,将两部分尺寸输入到AutoCAD中自动绘图标注显示最终测量结果.实验结果表明:该系统具有较高的测量精度,基本满足实际测量中快速、高精度的要求. 相似文献
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激光基准成像测量光斑图像的亚像素检测算法 总被引:1,自引:0,他引:1
在激光基准下基于CCD成像身管轴线直线度测量系统中,对激光光斑图像的高精度检测和定位是影响系统测量精度的一个重要因素.为了提高激光光斑图像的检测和定位精度,提出了一种Sobel-Guass拟合算子的激光光斑亚像素边缘检测方法,同时结合最小二乘迭代圆拟合法设计了光斑中心的高精度定位.即:首先用Sobel算子细化边缘,进而在梯度方向上进行高斯函数拟合插值,进一步提高图像边缘位置的检测精度,最后经最小二乘圆迭代拟合后得到激光光斑的亚像素级几何参数,从而使测量系统的精度提高一个数量级.实验结果表明:像素细分后对像素点的定位精度可以达到0.1个像素,亚像素边缘对标志中心的定位精度优于0.03像素. 相似文献
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角点检测能否达到亚像素精度对视觉系统精度有很重要的影响。本文分析了空间矩亚像素算法基本原理及其原理误差的产生的原因,并在角点提取中采用任意角度边缘的误差函数对误差进行校正,实验数据表明,通过误差校正后角点检测精度大大提高,而且减少了以往使用校正表带来的计算量、查寻时间和存贮空间等。 相似文献
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亚像素算法是一种高精度的边缘检测算法.分析了亚像素边缘检测的原理及现有算法的优缺点,根据现有用亚像素对表面贴装元器件图像检测的算法,提出了三次样条插值的亚像素算法进行边缘提取.通过实验比较,认为该方法提高了边缘提取的精度,满足了贴片机视觉检测的要求. 相似文献
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QU Ying-dong LI Rong-de YUAN Xiao-guang HUANG Hong-jun LI Chen-xi 《光电子快报》2007,3(5):376-380
In original Zernike moments subpixel edge operator, ideal step edge model is chosen for calculating four parameters of a pixel point, and therefore principle deviation is caused by edge model. In order to discuss the effect of principle deviation on edge location, sampled edge model is chosen for calculating edge parameters, principle deviation of edge translation l is derived based on Zernike moments edge detection theory, and modified formula of l is given for Zernike moments operator with masks of 5×5 size. Both theory analysis and testing result demonstrate that principle deviation is zero when edge translation l is limited in central pixel of a sampled window. In another case, the modification of l should be considered, which results in edge location accuracy of non-subpixel level for this subpixel edge operator. 相似文献
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A microprocessor-controlled line scan camera system for measuring edges and lengths of steel strips is described, and the problem of subpixel edge detection and estimation in a line image is considered. The edge image is assumed to change gradually in its intensity, and the true edge location may be between pixels. Detection and estimation of edges are based on measurement of gray values of the line images at a limited number of pixels. A two-stage approach is presented. At the first stage, a computationally simple discrete-template-matching method is used to place the estimated edge point to the nearest pixel value. Three second-stage methods designed for subpixel estimation are examined. The modified Chebyshev polynomial and the three-point interpolation method do not require much knowledge on the shape of the edge intensity. If the functional form of the edge is known, a least-square estimation method may be used for better accuracy. In the case of nonstationary Poisson noise, a recursive maximum-likelihood method for the first-stage edge detection, followed by subpixel estimation, is proposed 相似文献
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直线是视觉测量中的主要基元特征.提出了一种新的空间直线的三维重建算法.首先利用LOG算子进行快速像素级定位,再在包含边缘点的邻域内利用空间矩进行亚像素定位法,建立了考虑镜头畸变的双目视觉空间直线重建数学模型,在对边缘点进行去畸变处理的基础上,采用Hough变换与最小二乘相结合的方法获得像面直线,由双目视觉实现了空间直线重建.实验结果显示,在工件与两摄像机相距20 cm左右时,工件测量误差小于0.02 mm,说明该像面直线提取与空间直线重建方法具有较高的精度.Abstract: Beeline is an important element in the computer vision measurement. A new 3-D reconstruction of spatial beeline is proposed. First the LOG operator is used to locate the edge at the level of pixel quickly, and then the spatial moment is used to detect the subpixel location of the discrete points of edge. The least square fitting is adopted to fit the subpixel edge points which have been detected by Hough transform, after having gotten rid of the camera lens distortion. Mathematics model of reconstruction of spatial beeline from image lines on two image planes is set up. The experiments show that the measurement error is less than 0.02 rnm, as the workpiece is away from the two cameras about 20 cram, and 3-D reconstruction arithmetic of spatial beeline has acquired high precision. 相似文献
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为提高检测准确性,提出激光三角法高精度测量模型,由变阈值亚像素灰度重心提取算法和CCD倾角误差补偿模型两部分组成;光斑中心定位算法对激光检测准确度起关键作用,针对已有激光中心定位算法的缺陷,提出了变阈值亚像素灰度重心提取算法,通过梯度函数和高斯拟合算法设定阈值去除光斑边缘噪声区域对中心定位的影响,并利用多项式插值提高灰度重心法精度;同时为提高实际工业生产环境中的测量准确性,建立CCD倾角误差补偿模型;应用激光三角法高精度测量模型,以STM32F407为硬件核心建立系统,以锥螺纹为被测物进行实验;实验结果表明:该测量模型实现了对锥螺纹信息的准确采集,且精度明显高于传统的灰度重心法,可以将锥螺纹检测的误差控制在10 m内。 相似文献
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《Vision, Image and Signal Processing, IEE Proceedings -》1995,142(5):304-312
One approach to the detection of curves at subpixel accuracy involves the reconstruction of such features from subpixel edge data points. A new technique is presented for reconstructing and segmenting curves with subpixel accuracy using deformable models. A curve is represented as a set of interconnected Hermite splines forming a snake generated from the subpixel edge information that minimises the global energy functional integral over the set. While previous work on the minimisation was mostly based on the Euler-Lagrange transformation, the authors use the finite element method to solve the energy minimisation equation. The advantages of this approach over the Euler-Lagrange transformation approach are that the method is straightforward, leads to positive m-diagonal symmetric matrices, and has the ability to cope with irregular geometries such as junctions and corners. The energy functional integral solved using this method can also be used to segment the features by searching for the location of the maxima of the first derivative of the energy over the elementary curve set 相似文献